Manually operated rotary switch and combination load contact-fuse clip therefor

ABSTRACT

A low profile heavy duty manually operated double break electrical switch having a molded insulated housing with interior walls dividing the interior of the housing into isolated switching chambers for the different phases to be switched. A rotor journalled by the housing mounts a plurality of switching blades which respectively engage separate line and load contacts. Each load contact is formed from a strip of metal and is supported by a separate support member, which spans a switching chamber and is secured to the dividing walls of the switching chamber to mount the load contact in depending relation at a midpoint of the load contact in depending relation at a midpoint of the support to provide resiliency and minimize mechanical stresses imposed on the housing and enhance the accuracy of alignment. The load contact includes a fuse clip portion positioned below the support at the same level as the switch contact portion to minimize the housing profile and the support is notched to expose the fuse clip portion for the vertical insertion of the blade of a cartridge fuse. The fuse clip portion is bifurcated and reinforced by springs which span the closed end thereof. Variant load contact designs not requiring housing modifications for mounting are disclosed.

United States Patent. [191 Pekrul et al.

[451 Oct. 8, 1974 1 MANUALLY OPERATED ROTARY SWITCH AND COMBINATION LOADCONTACT-FUSE CLIP THEREFOR [75] Inventors: Ronald G. Pekrul,Southington;

' Louis T. Stegmaier, Plainville, both of Conn.

[73] Assignee: General Electric Company, New

' York, NY.

[22] Filed: Aug. 20, 1973 [21] Appl. No; 389,979

[52] U.S. C1 200/284, 317/114, 200/5 R, 200/15, ZOO/51.04, 337/9,339/252 F [51] Int. Cl. H0111 9/10, H02b H18 [58] Field of Search317/114; 339/252 F, 253 F, 339/256 C, 258 F, 259 F, 262 F; 200/5 R, 11R, l4, 15, 155 R, 166 E, 166 BH, 5 R, 51.04, 170 A, 275, 274; 337/9,190, 208, 209, 213, 215

[56] References Cited UNITED STATES PATENTS 1,040,331 10/1912 Horton339/253 F 2,199,793 5/1940 Hammerly 339/253 F 2,767,283 10/1956 Jung339/252 F 2,924,809 2/1960 Wilson 339/258 F 3,114,024 12/1963 Tillson200/293 3,188,404 6/1965 Fichter 200/14 3,705,374 12/1972 Stanb'ack200/166 E 3,778,566 Gusaras 200/14 Primary Examiner-Robert K. SchaeferAssistant Examiner-Gerald P. Tolin Attorney, Agent, or Firm-R. A.Cahill; P. L. Schlamp; F. L. Neuhauser ABSTRACT A low profile heavy dutymanually operated double break electrical switch having a moldedinsulated housing with interior walls dividing the interior of thehousing into isolatedswitching chambers for the different phases to beswitched. A rotor journalled by the housing mounts a plurality ofswitching blades which respectively engage separate line and loadcontacts.

naefiram'eaniaermainred t ro' rfiastripoi metaland' is supported by 'aseparate support member, which spans a switching chamber and is securedto the dividing walls of the switching chamber to mount the load contactin depending relation at a midpoint of the load contact in dependingrelation at a midpoint of the support to provide resiliency and minimizemechanical stresses imposed on the housing and enhance the accuracy ofalignment. The load contact includes a fuse clip portion positionedbelow the support at the same level as the switch contact portion tominimize the housing profile and the support is notched to exposethefuse clip portion for the vertical insertion of the blade of acartridge fuse. The fuse clip portion is bifurcated and reinforced bysprings which span the closed end thereof. Variant load contact designsnot requiring housing modifications for mounting are disclosed.

9 Claims, 6 Drawing Figures MANUALLY OPERATED ROTARY SWITCH ANDCOMBINATION LOAD CONTACT-FUSE CLIP THEREFOR This invention relatesgenerally to electric switches of heavy duty ratings and is particularlyapplicable to manually operated rotary switches having low profilehousings and to a new and improved combination load contactfuse clipunit which is economical to manufacture and is suited for use in suchswitches having a wide range of ratings and variations.

v Manually operated fused enclosed electric switches having ratingsofthe order of up to 100 a., 240 v. or more have heretofore commonlyemployed a handle operated rotary switch in series with a fuse in eachof the phases of the protected electrical circuit. Typically, the loadcontact in such a switch is selectively engaged and disengaged by amovable blade of the rotary switch for closing and opening the switchand is cantilever supported in spaced parallel relation with the movableblade by an upstanding interior wall of the molded insulated housing ofthe switch. The fuse clip for receiving one end of the associated fusefor such a load contact has commonly been positioned above the loadcontact to project in the opposite direction from the load contact andhas been clamped to the load contact by suitable fasteners. Since thearea of effective contact between the load contact and the fuse clipdoes not extend to the full'cross-section of the joint therebetween,heat was generated by the heavy I currents passing through the joint.Moreoventhe projection of the load contact and the fuse clip in oppositedirections has required a housing sufficiently deep to accommodatecombined heights of these assembled parts. I

It is an object of the present invention to provide a unique loadcontact-fuse clip unit which is economical to manufacture andis-efficient and durable in use.

Another object of this invention is to provide a new and improvedcombination load contact-fuse clip which can be fabricated by simplebending and punching operations and which minimizes the quantity ofcopperrequired therefor.

A further object of this invention is to provide a new and improvedcombination load contact-fuse clip unit which is provided with animproved alignment and support arrangement.

Still another object of this invention is to provide a fused manuallyoperated rotary switch incorporating a combination fuse clip-loadcontact unit which accommodates a lowprofile switch housing.

. Still anotherobject of this inventionis to provide a manually operateddouble break rotary switch having a combination load contact-fuse clipunit mechanically supported in the switch housing by a support memberwhich spans the unit for improved mechanical support and alignmentaccuracy.

Other'objects will be in part obvious and in part pointed out more indetail hereinafter.

A better understanding of the invention will be obtainedfrom thefollowing detailed description and the accompanying drawing of anillustrative application of the invention.

In the drawings: j

FIG. 1 is a side view, partly broken away, of a fused manually operateddouble break rotary switch incorporating'the present invention;

FIG. 2 is a framentary top view of the switch mechanism of FIG. 1;

FIG. 3 is across-sectional view taken along the lines 33 of FIG. 1;

FIG. 4 is a side view of the load contact-fuse clip of the presentinvention;

FIG. 5 is an end view of a variant form of the combination load contactfuse clip unit of the present invention, and

FIG. 6 illustrates another variation of the present invention.

To describe the invention in further detail, there is shown in FIG. 1, aheavy duty fused manually operated double break rotary electrical switchwhich is housed in an insulating enclosure 10 which journals a rotor 12in the end wall thereof. The rotor 12 is, provided'with a squareextension 13 through one of the end walls for connection to a handle,not shown, for the manual operation of the rotor.

The rotor 12 mounts a plurality of switches 14 having switch blades 15for rotation therewith. As shown,

switch blades 15 comprise a pair of parallel blades l6, l8 engageablewith the load and line contacts 20, 22 (FIG. 3) to form a double breakswitching arrangement for opening and closing the switch. I

The switch 14 of only one of the phases of the protected line is fullyillustrated. However, identical switches such as switch l4a, arepositioned axially along the rotor 12 for each phase of the protectedcircuit.

Associated with each of the contacts 20, 22 are arc enclosures 26, 28,respectively, which serve to shield the arc generated between the bladesof the switch 14 and the contacts 20, 22, respectively, as the switch isbeing opened, it being understood that the flexure of the blades 1 6',l8 against the bias of springs 17 causes the blades to resiliently gripthe contacts 20,22 when the switch is closed. A fuse (shown in phantom)having a blade 30 is shown as being connected in series with the rotaryswitch 14. The blade 30 of the fuse is resiliently received in thereceiving slot 36 of the spaced parallel upstanding legs 32, 34 as bestshown in FIG. I.

As shown in FIG. 4, the leg 34 is bifurcated so that each of thebifurcated portions 34a, 34b is resiliently biased into engagement withthe blade 30 of the fuse independently of the other. This coupled withthe upset dimples 70 assure contact between the blade. 30 and the fuseclip despite anymisalignment of the blade 30 and the receiving slot 36of the fuse clip. Projections 38 retain the fuse blade within the slotunder short circuit conditions. It will be noted that each of thebifurcated portions 34a, 34b of the leg 34 are directly backed by theleg 32 of the fuse clip so. that the blade 30 is clamped directlytherebetween. Flat reinforcing springs 35 span the closed end of thefuse clip and projections 40 of the spring are received in notches 42provided in backing leg 32 to fix each reinforcing spring 35 inassembled position to reinforceand bias each of the bifurcations 34a,34b toward the backing wall provided by leg 32. The springs 35 areformed of a spring steel having a high yield strength and elongation toreinforce and bias the legs 32, 34 of the fuse clip into good electricalcontact with the fuse blade 30 throughout the life of the switch despiteany fatigue which may take place in the copper forming the fuse clipduring use.

As will be apparent from the drawings, the combination fuse clip loadcontact is formed from a unitary strip of copper by being bent into agenerally S-shape configuration by a simple bending operation and theshape and upset portions of the combination unit may be produced in asimple punch press operation. As a result, a load contact fuse clipconstruction formed from a single piece of stock having the maximumcurrent carrying capacity can be produced economically.

Referring particularly to FIGS. 1 and 2, the combination loadcontact-fuse clip unit is provided with a support member 44 which isformed separately therefrom and is connected to the combination loadcontact-fuse clip by fastening screws 46 engaging horizontal wall 45formed intermediate the fuse clip and load contact portions thereof. Thesupport member 44 spans, or extends laterally beyond the load contactand fuse clip in both directions and is secured by fasteners 48, 50, re-

spectively, to upstanding walls 54, 56 which define a switching chamberisolated from like switching chambers for the switches of the otherphases. Not only does this construction provide high accuracy ofalignment of the load contact and fuse clip with the housing and therotor blades of rotor 14, due to the distance between the points ofsupport provided by the screws 48 and 50, but also this constructioncauses less mechanical stresses to be imposed on the housing as a resultof the sudden opening of the switch or the replacement of the fuse. Asbest shown in FIG. 2, a corner of support member is cut away at 52 toexpose the receiving slot 36 between the legs of the fuse clip toaccommodate the downward insertion of the blade 30 of a cartridge fuse.A pair of apertures in the support member receive the upstandinglocators 53 molded in the enclosure for additional alignment accuracy.

As shown in FIG. 1, the fuse clip and load contact are disposed on oneside of support member 44 and at the same horizontal level so. that thehousing may have a low profile as compared with a heretofore commonlyused design in which the fuse clip was disposed directly above the loadcontact.

Since in the design of the present invention, the wall 58 which servesthe function of isolating the are produced by opening the switch for onephase from the switch for an adjacent phase by contributing to theminimum required surface and air distance between the arcs produced byadjacent switches and is not required to withstand the mechanicalstresses which would be imposed on a fuse clip-load contact cantilevermounted thereon, it may be narrow, thereby minimizing the axial lengthof the housing which would otherwise be required.

In the variant of FIG. 5, a separate adapter or insert 60 is shown asbeing inserted in the slot 36 of the fuse clip in order to accommodatethe blade 61 of a fuse of a lower rating so that a single loadcontact-fuse clip component can be utilized for a wide range of currentratings. The adapter 60 has an apertured horizontal wall 62 and adepending wall 64 positioned in blade receiving slot 36 and provides aformed projection 65 to position the fuse blade in the slot 36 and issecured in position by screws 46. i I

The variant illustrated in FIG. 6 is illustrative of a' modified form ofthe invention wherein the rotor 14 comprises a single blade rotor 14aand the load contact is formed of a pair of spaced parallel legs 20, afor receiving the single blade 14a therebetween. The modified loadcontact of this variant is supported by the support member 44 in thesame manner as with the other design so that no modifications of thehousing or change in the assembly of the load contact in the housing isrequired.

FIG. 6 also illustrates another variant of the design wherein a fuse isnot used in the switch. A terminal 66 is connected directly to the loadcontact by a stud 68 and the fuse clip portion is eliminated.

From the foregoing, it is apparent that this invention provides animproved adaptable, high performance, combination load contact-fuse clipunit suited for use in a wide range of switch ratings and variantswherein the housing may have a low profile and does not need to bemodified for the several variants. It is further apparent that theforces imparted to the housing by the support of the combination loadcontact-fuse clip unit are significantly reduced from designs heretoforeused and do not involve any cantilever mounting thereof.

As will be apparent to persons skilled in the art, variousmodifications, adaptations and variations of the foregoing specificdisclosure can be made without departing from the teachings of thepresent invention.

We claim:

1. A low profile, heavy duty rotary switch comprising an insulatedhousing having interior walls dividing the interior of the housing intoa plurality of switching chambers for isolating the contacts of thecircuits of different phases to be controlled by the switch from eachother, a rotor journalled by said housing and mounting a plurality ofswitching blade means for rotation therewith, said switching blade meansbeing axially spaced along said rotor with each of said switching blademeans being positioned in one of said switching chambers, a load contactpositioned in each of said switching chambers to cooperate with: anassociated switching blade means for opening and closing one of thecircuits, a support for each said load contact, each said supportspanning each respective switching chamber and mounted by the walls oneach side of the chambers, said load contacts extending downwardly fromsaid supports between said walls and parallel to the plane of rotationof each said switching blade means, and means securing each said loadcontact to each said support intermediate the ends of said supports.

. 2. A switch as recited in claim 1 wherein each said load contact isformed from a strip of metal and is of a generally S-shapedconfiguration to provide a fuse clip portion having a pair of spacedlegs generally disposed below each said support for gripping the bladeof a cartridge fuse therebetween.

3. The switch defined in claim 2 wherein the means for securing eachload contact to each support is disposed intermediate the fuse clip andload contact portions thereof.

4. The switch defined in claim 2 wherein each support is notched toexpose the fuse clip portion to accommodate the downward insertion ofthe blade of a cartridge fuse.

5. The switch defined in claim 2 wherein one leg of each fuse clipportion is bifurcated so that each bifurcated portion thereofindependently biases the blade of a cartridge fuse directly against thebacking wall provided by the other leg of each fuse clip portion.

6. The switch recited in claim 5 wherein a U-shaped reinforcing springspans the closed end of each bifur- 6 of each said switching blademeans, and line contacts engageable with the other end of each saidswitching blade means are provided to form a plurality of double breakswitches.

9. The switch recited in claim 1 wherein a cable con nector is mountedby each said load contact.

1. A low profile, heavy duty rotary switch comprising an insulatedhousing having interior walls dividing the interior of the housing intoa plurality of switching chambers for isolating the contacts of thecircuits of different phases to be controlled by the switch from eachother, a rotor journalled by said housing and mounting a plurality ofswitching blade means for rotation therewith, said switching blade meansbeing axially spaced along said rotor with each of said switching blademeans being positioned in one of said switching chambers, a load contactpositioned in each of said switching chambers to cooperate with anassociated switching blade means for opening and closing one of thecircuits, a support for each said load contact, each said supportspanning each respective switching chamber and mounted by the walls oneach side of the chambers, said load contacts extending downwardly fromsaid supports between said walls and parallel to the plane of rotationof each said switching blade means, and means securing each said loadcontact to each said support intermediate the ends of said supports. 2.A switch as recited in claim 1 wherein each said load contact is formedfrom a strip of metal and is of a generally S-shaped configuration toprovide a fuse clip portion having a pair of spaced legs generallydisposed below each said support for gripping the blade of a cartridgefuse therebetween.
 3. The switch defined in claim 2 wherein the meansfor securing each load contact to each support is disposed intermediatethe fuse clip and load contact portions thereof.
 4. The switch definedin claim 2 wherein each support is notched to expose the fuse clipportion to accommodate the downward insertion of the blade of acartridge fuse.
 5. The switch defined in claim 2 wherein one leg of eachfuse clip portion is bifurcated so that each bifurcated portion thereofindependently biases the blade of a cartridge fuse directly against thebacking wall provided by the other leg of each fuse clip portion.
 6. Theswitch recited in claim 5 wherein a U-shaped reinforcing spring spansthe closed end of each bifurcated portion to bias the same toward thebacking wall provided by the other leg.
 7. The switch of claim 1 whereineach switching blade means comprises a pair of parallel blade memberswhich grip each load contact therebetween.
 8. The switch defined inclaim 7 wherein each switching blade means extends in both directionsfrom the rotor, each said load contact is engageable with one end ofeach said switching blade means, and line contacts engageable with theother end of Each said switching blade means are provided to form aplurality of double break switches.
 9. The switch recited in claim 1wherein a cable connector is mounted by each said load contact.